1. Field of the Invention
The present invention relates to a movement detection device, an electronic device, a movement detection method, and a storage medium stored with a program, and in particular to a movement detection device, an electronic device, a movement detection method, and a storage medium stored with a program that detect movement by employing a tri-axial acceleration sensor.
2. Description of the Related Art
Conventionally, in an electronic device, such as a mobile phone or the like, a tri-axial acceleration sensor is internally provided, acceleration component data is detected for each axial direction of the tri-axial acceleration sensor, and computation of the inclination angle of the electronic device is performed.
During computation of the inclination angle of the electronic device, sometimes the inclination angle cannot be accurately computed if an external disturbance occurs, such as from a vibration function or the like. Therefore, there is a proposal for a portable electronic device in which acceleration values, these being the magnitude of acceleration vectors, are computed from tri-axial acceleration data detected by the tri-axial acceleration sensor, and when the difference between the acceleration value and the acceleration value in a stationary state is a specific value or greater, determination is made that external disturbance has occurred, and the inclination angle is computed without using the acceleration data during occurrence of the external disturbance (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2009-89048).
There is also a proposal for a mobile electronic device in which acceleration data is detected by an acceleration sensor provide internally to a mobile phone, the amount of inclination for each of three axes is computed and which of the faces of the mobile phone faces in which direction is ascertained with the ground as a reference, the acceleration occurring when a particular face of the mobile phone is tapped is detected, determination is made as to whether or not the applied acceleration is a threshold value or greater, and the face to which force has been applied is computed (see, for example, JP-A No. 2009-33651).
However, in the technology of above JP-A No. 2009-89048, while the presence or not of external disturbance can be determined, since the direction movement occurring due to the external disturbance cannot be determined, when performing a specific input operation, as with motion input by making the electronic device move in a specific direction, it is only suitable for one type of input, and plural operations cannot be accommodated.
In the technology of JP-A No. 2009-33651, the direction and magnitude of the acceleration applied is computed by using vector summation, however there is no specific reference therein as to whether there is correspondence assigned in any manner between the direction of the vector sum and each axial direction, and sometimes the axial direction cannot be accurately determined.